The drone fired two missiles at a suspected militant compound at a village outside Miranshan, the main town in North Waziristan, killing five suspected insurgents, the officials said.

A second drone strike killed seven suspected insurgents in a village near Mir Ali, North Waziristan, the officials said.

The drone fired three missiles at a suspected militant vehicle, they said.

The officials asked not to be named because they are not authorized to speak to the media.

North Waziristan is one of seven districts in Pakistan's tribal region and widely believed to be a sanctuary for the Haqqani network and other militant groups that fuel the insurgency across the border in Afghanistan.

Based on a CNN count, Thursday's drone strikes were the sixth and seventh this year. There were more than 60 drone strikes last year and more than 110 in 2010.

The attacks have killed scores of militants, but human rights groups say the strikes have also killed hundreds of civilians, including children.

The United States does not publicly acknowledge its drone program, although President Barack Obama commented on such strikes in January and Defense Secretary Leon Panetta acknowledged the use of CIA predator drones in the region last year.